The inequality (REF ), which is the main result of this paper, gives an upper bound
to the gains that informed traders can extract from their side information.
Combined with the derivation in the previous section, it shows
that the maximal profit that informed traders can gain cannot exceed the
maximal work that can be extracted from the analogous physical system (the Szilárd
information engine). This reveals a precise analogy between
the generalized second law of thermodynamics (REF ) and a
generalised efficient market hypothesis, for the GM model.
The asymptotic statements (REF ) and (REF ), on the other hand, says that
for \(\nu \rightarrow 0\)  the approach of the price \(p_t\)  to its asymptotic value \(Y\)  becomes infinitely slow,
resembling a quasi-static limit in thermodynamics. In this limit, the transactions of informed traders are
well separated in time and the market has enough time to relax to an equilibrium dominated by noise
traders, as in a reversible process. Eq. (REF ), hence, is consistent with the
observation [1]} that the generalised second law of thermodynamics holds as
an equality for reversible feedback protocols.
